Patterns of co-occurrence of stream insects and an examination of a causal mechanism: ecological checkerboard or habitat checkerboard?
Article first published online: 4 APR 2012
© 2012 The Authors. Insect Conservation and Diversity © 2012 The Royal Entomological Society
Insect Conservation and Diversity
Volume 6, Issue 2, pages 105–113, March 2013
How to Cite
McCREADIE, J. W. and BEDWELL, C. R. (2013), Patterns of co-occurrence of stream insects and an examination of a causal mechanism: ecological checkerboard or habitat checkerboard?. Insect Conservation and Diversity, 6: 105–113. doi: 10.1111/j.1752-4598.2012.00191.x
- Issue published online: 15 MAR 2013
- Article first published online: 4 APR 2012
- Accepted 5 January 2012 First published online 4 April 2012 Editor: Yoshitaka Tsubaki Associate editor: Ignacio Ribera
- habitat checkerboards;
- null models;
Abstract. 1. Non-random patterns of species co-occurrences among habitats and the underlying mechanisms responsible for these patterns are fundamental to ecological research. Fewer co-occurrences than expected from a random null model are often interpreted as indicating that communities are structured by negative biotic interactions (ecological checkerboards) or by abiotic factors (habitat checkerboards). The difficulty has often been determining the dominant causative mechanism(s) behind these patterns.
2. In the current study, we examine patterns of insect co-occurrence in 23 low-gradient, sandy-bottom coastal streams of the Gulf of Mexico. Focusing our attention on five commonly collected orders in these sites, we ask two fundamental questions about the community: (i) Are patterns of insect co-occurrence non-random? (ii) If these patterns are non-random, are they consistent with the expectations of a community structured largely by abiotic conditions, biotic conditions (e.g. species interaction) or both?
3. Using a series of null models, we found a strong pattern of negative co-occurrence (segregation) for both genera and species when all stream sites were considered. When we partially controlled for the influence of abiotic conditions by examining a subset of streams with similar abiotic conditions, both species and genera showed a very significant pattern of aggregation. These results therefore suggest that abiotic conditions act as a strong filter, influencing the patterns of co-occurrence for both genera and species.
4. Comparisons of co-occurrence patterns between the species-level and genus-level analyses suggested similar degrees of segregation. Thus, no compelling evidence of competition influencing insect distributions among streams was found.